'New Zealand is as close as we will get to the opportunity to study life on another planet.' (Diamond 1990) Although the physical environment has been described as a habitat template for animals (Southwood 1977 ), many animal species can also significantly modify their surroundings (Johnston 1995). The New Zealand fauna has numerous examples of both, as well as many ancient taxa that have evolved into unusual forms. In this chapter we examine animal habitat in natural and human-modified environments. We begin by examining the geological origins and biogeographic patterns of New Zealand animal species diversity and community composition. These biogeographic patterns will be explained in terms of general ecological concepts of limiting factors and environmental gradients. Every animal species is adapted to a specific combination of environmental characteristics, referred to as the species' ecological niche. Areas with these specific environmental characteristics define the species' habitat. The transformation of natural landscapes for human land use has significantly fragmented the habitat of many native animal species. We end this chapter by examining the effects of human landscape transformation and animal invaders on the New Zealand environment and native animal species.